Tag Archives: digital

Changing Band Conditions

For the past three or four months I was having great success early in the morning with 40m JT-65 contacts to Asia on the 1/4 wave vertical antenna. The band would be great at around 6:45 am and be open till around 8:30 am. Japan especially would be easy to make contacts with on JT-65.

I have been noticing a definite shift in early morning 40m to Asia. First, I should note that JT-65 activity has dropped off quite a bit now that FT-8 is getting so rapidly popular. Just in the last few weeks I have noticed a drastic reduction in the number of JT-65 spots showing on pskreporter. The second observation is that the band seems to open to Asia a bit later now from about  7:30 am to about 8:30 am.

So this morning I started out trying JT-65 and made two contacts to Japan but there were very few signals on the waterfall. FT-8 had much more activity overall. I switched to FT-8 and started calling CQ DX and the first response was from Indonesia. The next 8 QSO’s were from Japan.

Overall, I have mixed felling about this. I enjoy the early morning pace of JT-65. I can check my emails while checking the bands. FT-8 takes quite a bit more work and attention. One other effect is that FT-8 is a bit more difficult to close a weak signal QSO. It is easy for the signals to drop below the noise floor and disappear between transmissions.

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Ham Shack Changes – Part II

Configured a Pelican case to carry the FT-450D and an MFJ-4230MVP 12V power supply along with the microphone and assorted cables. The case has two “levels” so there was plenty of room. I plan to use the FT-450D portable with antennas that can be matched with the internal 3:1 tuner. So this is my FT-450D “go-kit”:

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I have a QRP version of this with the FT-817ND in another case. There is also a smaller case now which holds the Netbook and cables needs to connect either rig for digital modes. I have one more smaller pelican case to configure for solar charged portable operation with the LiFePo batteries.

Exploring a New Digitial Mode: FT8

Joe Taylor is testing a new digital mode called FT8. The development version of WSJT-X software now supports this mode. FT8 ( Franke-Taylor design, 8-FSK modulation) works similar to the more familiar JT-65 and JT-9 modes except the T/R cycle completes in just 15 seconds thus greatly reducing the time to complete a QSO. The bandwidth of the signal is 47 Hz and the decoding threshold is -20dB.

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I downloaded the development version this morning and tried FT8 on 40m. There were just a few signals but I did close my first QSO. Pskreporter showed my signals was also being received in Australia this morning. Some things to note: Logging may not work and I understand that LoTW does not recognize FT8 as of yet. Also, the software autoexecutes the T/R sequence once the QSO starts. You have less than 2 seconds to select the station to respond too!

 

Post Field Day Report

I got a late start to field day this year due to a late breaking family commitment. Our club tried to setup at the local weather station but cancelled operations due to a large noise source crashing the bands at that location.

I started operating about 19:30 UTC. I started at 5W on SSB but over the first hour only made one contact. The band conditions were not good on 20m with lots of QRM and QSB. I added the amplifier and started to work on 45W. My power draw was significantly higher but my Q rate increased. The solar panel kept up with the power consumption even though there was quite a bit of cloudiness. I continued to operate on 20m until dusk when I switched to 40m. Overall I made 60 Phone contacts over the course of about 8 hours. My score this year will be lower even with more Q’s due to the higher power I ran. I did not get a chance to run digital.

What worked:

  1. Digital logging – netbook needed one charge cycle during this period. The 12V to 18V DC-DC converter was running at abou 2.2A during the charging cycle. I used a 7Ahr for this through a spare Solar Charge controller. I am going to look at a tablet for next year.
  2. The EFHW antenna worked great on 20m.
  3. SOTAbeams travel mast + TV tripod worked great to support antenna with no guy lines.
  4. Solar generator box had enough juice to supply the day’s activity even at the higher power consumption and had some power to spare.
  5. Tube Tarp came in real handy as shade. Luckily no rain on Saturday. I’ll do better with the depolyment next time as I figured out how to guy it better.

What did not work so good:

  1. Can’t run digital mode while using an amp. The amp uses the ACC port on the radio but provides no pass through. I am looking at how I can accomplish this for next time.
  2. I don’t have the battery budget to run 45W phone for 24 hours. I figure I would have run out of power after about 12 hours. Partly cloudy day didn’t help.
  3. Didn’t take advantage of more 6 stations to raise Q count.
  4. Calling CQ consumes a lot of power. Need to refactor the power budget.

So I figure my score this year for 60 SSB QSO’s + bonus points for emergency power will work out to 310 for my 1B station. I am convinced now that I have to finish learning CW so that next year I can run 5W on CW and up my point count. A more directional antenna would be nice but a portable beam antenna remains elusive. For some reason I seemed to be doing better with stations in California than on the more densely populated east coast.

In summary, A great afternoon of outdoor radio fun and already looking forward to next year.

Transmit Power Using JT-65

I came a cross a very helpful web page in determining the amount of power needed for JT-65. It is called dbCalc and allows you to enter your transmit power and signal report and then calculates what your report would have been with other transmit power levels. I tried this out today on 40m JT-65, lowered my power in half and still made several DX contacts to Japan and Argentina.  You can easily measure how your signal is doing at a given power by sending a CQ and then checking the Pskreporter reports. Feed these into dbCalc and you can optimize your power settings for given band conditions. I suspect that in most cases operators are using a lot more power than necessary to make JT-65 contacts which makes it harder for weaker signals to get through.

Operating this Weekend with a 1/4 Wave Vertical

The winds have died down a bit here at the QTH and the travel mast has been up about a week now. The duct tape on the joints may have something to do with it. On 40m, the antenna is a winner. Made contacts on SSB to Europe in late afternoon early evening on Saturday. Making JT-65 contacts into Japan is like shooting fish in a barrel on early mornings. On 20m, I run the antenna through the tuner and also made some DX into Europe and the South Pacific. I switched between the vertical and the horizontal DXtreme end fed antenna and found that the vertical can definitely hear signals that the horizontal cannot. Propagation conditions seems to be shifting these past couple of weeks. 40m is solid into Asia early morning and Europe in the early evening. 20m has been weak in the morning but picks up in the late afternoon. 17m has been really hurting lately with some small windows opening up from time to time. All in all a good weekend of radio activity.

Getting ARES Ready…Hurricane Season Approaches

Hurricane season officially begins on June 1st. Our local club is gearing up some activities to support ARES operations in the event of a storm. We will be setting up a 2m digital simplex net on Thursdays at 7pm local time on 146.580 simplex using MT63 2000. Net control will be Cliff, N5CEY.

I will be net control for an HF voice and HF digital net on Saturday afternoons. Times and digital modes are yet to be determined. NVIS operations on HF will be desirable for these nets. I suspect that my current antenna (the DXtreme 53′ end fed) works fairly well as NVIS as it is up horizontal no more than 20 feet up. This net will give me a chance to test the 40m magnetic loop as NVIS. I am also thinking of modifying the homebrew buddipole to work NVIS as well. There is a PDF file that shows a simple way to modify a Buddipole to work NVIS portable. Yet another option is to build an easily deployable NVIS antenna for 40m and 80m per these instructions (thanks DX Engineering).

I am looking into a few choices for HF digital modes. MT63 1000, PSK31, Olivia and NBEMS. I am thinking of eventually asking net participants to limit power to 20W max to simulate off grid operations.

Last but not least, getting more local hams to test their HF rigs on Winlink using WINMOR. I cranked up the IC-7100 this afternoon and easily sent some emails on 40m to a node in Houston on 20W. Here is a good tutorial on setting this up.

Been a Tough Week…

First week of 2017 was not too good here at the QTH. My second amazon branded USB hub died on me this week. This caused havoc again with my digital and rig control setups.These are getting hard to find in local stores so I ordered a 10-port hub from amazon. This one has a nice hefty power supply and is doing the job well.

Tuesday, my cable internet went down hard. Spectrum (formerly Time Warner) did not send a tech out until Thursday noon. Looks like the same issues as usual, i.e. low signal strength from the street. In goes an amplifier again at the cable box outside. They also replaced my cable modem for good measure. No internet means no spots on WSPR or Pskreporter let alone be able to work from home.

I attended my first CW academy class on Tuesday but had issues with Skype as I was using a cell phone hot spot. Got through the session but was not able to attend the second this week due to an unexpected family obligation. Overall, the class is going very well. I am sending better than I can read at this point but keeping up with the daily practice.

Snagged a Netbook

I was going through a local pawn shop earlier this week and came across a Gateway LT4004u netbook that had just hit the floor a couple of days earlier. It turns out to be in great shape with 2GB ram (maxed out), 150GB drive and a decent set of USB and other ports. I have been wanting a netbook for its size and low power requirements to work HF portable digital modes. This little unit fit the bill perfectly and for $60 I could not go wrong. I have ordered a 12V to 19V converter so that I can use this with my solar generator. I re-installed Windows 7 on it and after hunting a bit was able to load all the orginall drivers. Only thing I plan to add to it at this time is a Bluetooth dongle so that I can control my FT-817ND with a bluetooth CAT gizmo I acquired some time ago. Battery life on this looks quite good so I’d say I lucked out.

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HSMM Tests Planned

Another local ham, KB5ZCS, has setup a HSMM node and will be ready to test it this weekend. His QTH is 2.2 miles from mine and he will have the node up about 30 feet. I have dusted off my two nodes and updated the configuration to my new call sign. This should go without saying but don’t forget your password info when setting up your nodes! I did. Turns out there is a procedure for resetting it using “fail-safe” mode. Fortunately that worked!

I have ordered for overnight delivery two 9dBi antennas, a pair of PoE splitters and 50ft of cat 5 coax. The plan on my end is to hand the node up a 20 ft painters pole and see if we can make contact and measure signal strengths. If this works I can mount the node out side permanently on my VHF mast.I am looking to setup a linux server on a virtual machine so there is something to hook up to during the test.